<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <title>颜色_第3种表示_HEX或HEXA</title>
    <style>
        .atguigu {
            color: #ff0000;
        }
        .atguigu1 {
            color: rgb(138,43,226);
        }    </style>
</head>
<body>
    <h2 class="atguigu">尚硅谷</h2>
    <h2 class="atguigu1">尚硅谷</h2>
</body>
</html>